The present invention relates to a packaging machine for wrapping groups of products in related wrapping sheets made of heat-sealable material.
In the description that follows, the groups of products taken into consideration are groups of paper rolls, whereto the present description shall make explicit reference without thereby relinquishing its general nature.
Known packaging machine for paper rolls normally comprise a first wrapping unit to form a tubular case from a continuous strip of heat-sealable material and to stabilise the tubular case by a longitudinal sealing operation; a conveyor device to feed in succession groups of rolls, each whereof is constituted by a plurality of rolls positioned side by side to each, inside the tubular case; a separator device to separate, in succession from the aforesaid tubular case, tubular wrappers, each of which is wound around a related group of rolls, and has two open tubular ends projecting from the related group of rollers; and a second wrapping unit to fold each tubular end substantially in contact with the related group of rolls and to form an external case having two end superposition areas, which are stabilised by respective sealing operations.
The known packaging machines described above have some drawbacks, mainly deriving from the fact that such machines have relatively low flexibility because they are suitable to package the groups of rolls solely in one type of external case, i.e. in an external case obtained starting from the aforesaid tubular wrapper and by folding and stabilising the aforesaid open tubular end.